Rotary vane engine and thermodynamic cycle

ABSTRACT

A heat engine having a rotary vane compressor and a rotary vane turbine operates in a highly efficient thermodynamic cycle which includes a power expansion phase up to ambient pressure and a limited temperature constant volume combustion followed by a constant pressure combustion and/or a constant temperature combustion. A compound propulsion engine utilizing the thermodynamic cycle has a primary stage having an axial compressor and a rotary vane turbine, and a secondary stage having an axial turbine and a rotary vane compressor, the two stages being aero-thermodynamically coupled to each other without provision of an interconnecting drive shaft.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national stage application of copendingInternational Application No. PCT/TR03/00071, filed Sep. 9, 2003,claiming priority dates of Sep. 9, 2002 and Sep. 8, 2003, and publishedin the English language.

FIELD OF THE INVENTION

This invention relates to energy systems and more particularly tocomponentry and thermodynamic cycle for enabling shaft work, propulsiondrive, electric power source, jet propulsion and thermodynamic systemssuch as ventilation, cooling, heat, pressure or vacuum generatingsystems.

BACKGROUND OF THE INVENTION

Since the start of the industrial revolution, the reciprocating pistonengine based on the Otto and Diesel cycles and, the gas turbine enginebased on the Brayton cycle, have largely dominated the market. Despitethis fact, for many years, patents on rotary combustion engines haveclaimed that rotary engines possess many advantages over reciprocatingengines such as having high torque, fewer parts, lower weight and fewerreciprocating imbalance. Fundamental design characteristics is of thepresent invention addresses the main problems related to rotary enginesand bridges the mass flow and rotational speed gaps betweenreciprocating and gas turbine engines.

Avoiding Wear and Improving Sealing in a Vane Rotary Engine

One reason for the lack of industrial attention is that many rotaryengines have been faced by serious wear and sealing deficiencies. Themain cause of the wear is the centrifugal force generated during highspeed rotation that forces the vanes to scrap the inner peripheral ofthe working chamber. This has been recently addressed by using hingedvane central retention mechanisms (U.S. Pat. No. 5,352,295, Chou Yi,Oct. 4, 1994 and PCT WO 02/31318, VADING Kjell, Apr. 18, 2002). In suchconfigurations, the sliding vane is articulated through a cylindricalslideable guidance placed between the rotor and the vane. Whilecorrecting the wear problem, the number of moving parts has increasedand hence, the system became more complex. At worst, each one of saidparts increases the probability of engine failure due to wear andfatigue. At best, the pressure sealing, lubrication and coolingcapabilities of the vane mechanism deteriorates. In the presentinvention, the intermediary cylindrical slides are eliminated alltogether as the radially outer vane tips (86,109) are always in anatural contact with the housing inner peripheral (88,97). The basicreason for this natural contact is that the housing inner peripheral(88,97) is non-circular and has a cycloidal shape (FIG. 6) thataccommodates perfectly an eccentrically placed sliding vane of fixedlength (16,37,50,63,87,100,119, 125). The easy machining andmanufacturing technique disclosed in this invention, is based on theside enlargement of the largest fitting circle within the cycloid (FIG.6), and have not been mentioned by prior arts (U.S. Pat. No. 6,236,897,LEE and al., May 22, 2001; U.S. Pat. No. 5,996,355, Jirnov and al., Dec.7, 1999, U.S. Pat. No. 4,422,419, UMEDA, Dec. 27, 1983). The saidgeometry (FIG. 6), given in the detailed description and the relatedclaims of the invention below, has good sealing at all sliding vaneposition angles. Wear contacts generated by the sliding is vane tips(86,109) against the housing inner peripheral (88) are eliminated by apivot axle vane retention mechanism (54, 55, 61, 62, 81, 82, 104, 105)centrally placed within the rotor.

Rotary Engines with Sliding Vane Slicing Through Rotor

Instead of having hinged vanes, some of the prior arts do use slidingvanes slicing through the rotor (U.S. Pat. No. 4,414,938, UMEDA Soei,Nov. 15, 1983 and U.S. Pat. No. 4,422,419, UMEDA Soei, Dec. 27, 1983;U.S. Pat. No. 5,596,963, LAI, Jui, H., Jan. 28, 1997). In these arts, aplurality of spring-loaded vanes are used against the housing wall toachieve air-tightness. Therefore, they fundamentally differ from thespringless single “all-through solid” vane mechanism of the presentinvention. Furthermore, above-mentioned prior arts do not have anycentral vane retention mechanism (138, 139, 150) that would prevent therelated wear problem. Moreover, only a portion of the entire innerperipheral of the housing is elliptic. Another patent, related to rotaryheat engine with ‘all-through solid’ vane (U.S. Pat. No. 5,511,525,JIRNOV and al., Apr. 30, 1996), uses at least two mutually perpendicularvanes with radially extending guide. The plural use of vanes within onecompressor housing substantially reduces the pressure ratio. This leadsto a reduction of the rotary component efficiency and also increase thesystem complexity as more stage is required. Furthermore, the vane guidepath mechanism described in this prior art is an additional cause forincreased friction wear.

Rotary Engines with Separate Compression and Expansion Chambers

There are many rotary engine patents which provide separate compression,combustion and expansion chambers (PCT WO 02/31318, VADING Kjell, Apr.18, 2002; PCT WO 99/041141, O'BRIEN Kevin, Jan. 28, 1999; U.S. Pat. No.5,596,963, LAI, Jui, H., Jan. 28, 1997; U.S. Pat. No. 5,335,497,MACOMBER Bennie D., Aug. 9, 1994; U.S. Pat. No. 5,352,295, YI Chou, Oct.4, 1994; U.S. Pat. No. 5,235,945, TESTEA Goerge, Aug. 17, 1993).Actually, almost all rotary vane type engines produce very high torquebecause the combusted gas expands right against the hot section vane(37,63,100,119), which is the arm length of the generated torque.Therefore, not only is the crankshaft unnecessary, but when comparingengines of equal volumes, the power leverage on the drive shaft of arotary engine is greater than that of a corresponding reciprocatingengine. However, here too, there is room for improvement; the presentinvention overcomes the drawbacks and limitations of todays power andrefrigeration cycles by proposing and implementing new high efficiencythermodynamic cycles (151 abceh, 151 abcdfh, 151 abcgh)

Rotary Engine with Improved Thermodynamic Cycle

The present invention combines the advantages of Otto and Diesel cyclesat intake, compression and combustion phases of the thermodynamic cycleby limiting the peak combustion temperature. The present invention alsoclaims an expanded power stroke that greatly improves power extractionand efficiency. With a proper thermodynamic and geometrical match of thecompressor and turbine working chambers, it is shown that the expansionprocess can be improved and lower exhaust pressure and temperaturelevels can be achieved. A search of the prior art did not disclose anyrotary engine patent with separate compression and expansion chambersthat considers and provides an expansion process that would take thecombusted products further down to ambient pressure levels. The overlookof such thermodynamic cycle improvement is a major source of wastedenergy that ultimately translates in engine fuel inefficiency.Accordingly, the present invention provides proper sizing of thecompression and expansion chambers, the rotors, and the vanes so as toachieve optimum compression (151 ab), combustion (151 bce, 151 bcdf, 151bcg) and expansion (151 eh, 151 fh, 151 gh).

OBJECT OF THE INVENTION

One of the objects of this invention, is to increase the thermalefficiency above levels reached by today's heat engines. This isachieved by implementing a longer power extraction phase (151 eh, 151fh, 151 gh) and by realising high compression ratios with less shaftpower input, by processing the fluid through a smooth crescent shapeconstriction (72 and 49 and 53). Another object of the present inventionis to decrease the wear. Wear is minimised through the incorporation ofthe pivot axle vane retention mechanism (138, 139, 150) and by providingan efficient oil lubrication. The operational and maintenance costs arealso minimised, as maximum peak temperature is limited. All together,the present invention discloses an efficient, powerful, compact, simpleand reliable heat engine.

For the compound engine configuration of the instant invention, rotarycomponents and gas turbine engine components have been matched with eachother. The objective is to combine the high efficiency and “no-stall”characteristics of internal combustion engines with the high mass flow,smaller size and lighter weight characteristics of the gas turbineengines. Another objective is to eliminate the long, heavy andcumbersome concentric shafts and reduction gears that are present intoday's turbofan, turboprops and turbojet engines. By simplifying themechanical links and by integrating low mass flow rotary components, theimplementation of high efficiency reheat and intercooling systems havebecome extremely feasible.

SUMMARY OF THE INVENTION

The solo configuration (FIGS. 1,2,3,4) of the invention relates to arotary vane type machine comprising a compressor (10,19;46,48) and aturbine (36,43;57,59) housing, each having a crescent shape cavity. Eachof these housing is receiving an eccentrically placed rotor(4,11,89,96,117) equipped by a radially movable single sliding vane(50,63) arranged in the rotor. The rotor receives a centrally placedpivot axle vane retention mechanism, which is comprised of a pin (139)and a pivot axle (150). The pin head fits into the vane centre socket.Both ends or tips (86,109) of the sliding vane (87,100,119,125) areextending radially outward and are in contact with the cycloidal innersurface of the housing peripheral (88,97) at all rotational angles.Within each housing, depending on the rotational position of the slidingvanes, forms a plurality of working chambers (49, 53, 60, 66, 72) eachof the said chambers, delimited by the inner peripheral surface of thehousing (48, 59), the outer peripheral surface of the rotor (90,98) andthe side surface of the vane (16,37). With such configuration, the solouse of the turborotary engine of the invention overcomes the limitationsof conventional internal combustion engines and enables significantimprovement in power, torque and efficiency. The cycloidal housing innerperipheral eliminates any use of telescoping, articulated hinged vanemechanism and gives the engine of the invention a simple and naturallybalanced configuration.

For high mass flow rate, the present invention (FIGS. 8,9,10) extendsthe efficient but narrow operating range of the gas turbine engine bymechanically decoupling and eliminating the long shaft drive between theexpander (turbine) and the turbo-compressor. Each said fan (153, 155)and compressor group (158, 161, 182, 197) is allowed to be driven at itsown speed, by its own rotary turbine (154, 156, 157, 162, 181, 196)wherein, amounts of combustion fuel and air is delivered is dictated bythe instantaneous compressor load requirements. Turbines (170, 171, 178,191) drives rotary compressors (164, 166, 168, 179, 195, 190) that pumpshigh pressure fluid to respective rotary turbines. Therefore the presentinvention overcomes some of the off-design limitations of conventionalgas turbine engines. Because of their low mass flow rate requirements,it also becomes extremely, cheap and useful to equip the system withintercoolers (193) and reheat (198) systems. Other features, advantages,and applications of the invention will be apparent from the followingdescriptions, the accompanying figures, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated hereinafter through preferred andalternative embodiments wherein:

FIG. 1, is a schematic isometric view of a rotary engine wherecompressor (10) and turbine (43) housings are arranged in tandem. Thegas transfer from the compressor to the turbine is sequenced by a rotorsynchronised cyclo-valve. Combustion occurs within the turbine expansionchamber.

FIG. 2, is a schematic top view of the rotary engine of FIG. 1,sectioned at mid height of the turbine housing. Isometric view of thecyclo-valve (69, 70, 71) is added.

FIG. 3, is a schematic isometric view of a rotary engine wherecompressor and turbine housings are arranged in tandem. The gas istransferred from the compressor to the turbine through an intermediarycyclo-combustion chamber (74) synchronised with the rotational speed ofthe compressor and the turbine. Expansion occurs within the turbinechamber (103).

FIG. 4, is a schematic isometric view of a rotary engine wherecompressor (122) and turbine (121) housings are arranged back-to-backthereof, the compressor rotor (126) is coaxial with the turbine rotor(117). Combustion occurs externally within a cyclo chamber (114) andexpansion occurs within the turbine.

FIG. 5, is an exploded isometric view of rotor (135), sliding vane,sealing elements (131, 137, 140, 145, 146, 148), under seal springs(141, 143, 144, 147, 149), vane retention pivot axle (150) and pin (138,139).

FIG. 6, geometry of the cycloid machined by enlarging by ‘2δ’, thelargest circle of diameter ‘L’ that fits the housing peripheral (88,97)FIG. 7, high efficiency, high power, low peak temperature newthermodynamic cycles (151 abceh, 151 abcdfh, 151 abcgh) pertaining tothe invention.

FIG. 8, turbo-rotary-fan compound engine

FIG. 9, turbo-rotary-prop compound engine

FIG. 10, turbo-rotary compound engine for helicopter or powerapplications.

DETAILED DESCRIPTION OF THE INVENTION

The embodiments of the invention for which an exclusive privilege orproperty is claimed are described as follows:

FIG. 1 and FIG. 2 depict a preferred embodiment of the internalcombustion rotary engine where combustion occurs within the turbinechamber (66). FIG. 3 depicts a different preferred embodiment of anexternal combustion (74, 92) rotary engine where combustion starts in achamber (72) prior to entry within the turbine expansion chamber (103).The rotary combustion engine casing (21, 35,44) comprises at least onerotary compressor unit wherein, said unit has inner (19,48) and outer(46) housings. The engine casing also comprises at least one rotaryturbine unit wherein, said unit has inner (59) and outer (57) housings.Said housings are surrounded by a liquid cooled jacket (18,41,45). Forexample, water may be used as coolant. The housings have each, acircularly cylindrical (3, 13) rotor (12,128), rotatably andeccentrically mounted. The said rotary engine breathes through theintake (20) and exhaust (34,116) ports. The compressor rotor outerboundary (83,126) and turbine rotor outer boundary (98) are sealingly(101) mounted (90, 95) tangent to the chamber inner peripherals (88,97). Accordingly, the respective rotor outer boundary and the chamberinner peripheral are osculating at their common tangency plane (90, 95).As shown in more detail in FIG. 5, each of the said rotors (135) have aninternal vane groove (1) and many seal slots (118, 129, 134, 136) andoil cooling holes (2, 130, 133).

The sliding vane also carries many slots (14, 38, 40, 52, 64, 84, 124,120) that accommodates seals. The radially outer vane tips (86, 101,109) are always in a natural contact with the housing inner peripheral(88, 97). This is because the housing inner peripheral is non-circularand has a cycloidal shape that accommodates well an eccentrically placedsliding vane of fixed length. As seen from FIG. 6, The cycloidalperipheral (88, 97) is a unique shape, mainly depending on 4 parameters:the radial offset distance between the rotor center ‘o’ and the centerof the chamber ‘c’, the sliding vane length ‘L’, the seal height (145)and the seal spring (144). The dynamic and thermal loading behaviour ofthe seal spring under rotation and the circumferential temperaturedifferences may slightly alter the cycloidal shape.

The machining and the manufacturing of the cycloidal shape of thepresent invention is achieved by enlarging by a distance ‘δ’, bothopposite sides of the largest circle of diameter ‘L’ in such a way that,as the rotor rotates around its eccentrically placed axis over a range0°≦θ≦180°, the radially outer tips of the springless vane, define thesaid cycloidal shape of the housing inner peripheral. The exactcoordinates of such cycloidal shape is used in the precisionmanufacturing of the housing inner peripheral using modern manufacturingtechniques, including using CNC techniques

The pivot axle vane retention mechanism (54, 55; 61, 62; 81, 82; 104,105) is a unique mechanism where the pivot is always tangent to therotor central cavity (80). The pivot is a tubing (150) and retains thepin (139). which is embedded by one end into the sliding vane centersocket (FIG. 5). The pivot rotates at twice the speed of the pin and thevane. Roller, gear (not shown) or sliding head (55,81) of said pivotaxle is engaging the cylindrical rotor inner peripheral (80) to guidethe vane through its eccentric rotating and reciprocating slidingmotion.

Intake chamber (53) is receiving the fluid from intake port (20), saidfluid is either air, or any other working gas, or any other liquid-gasmixture. Said fluid, is compressed by the compressor rotor (12, 89) andthe single rigid sliding vane (50, 87) which is sealingly (86) andmovably mounted within the rotor groove. The sliding vane is contoured(127) to fit the said groove. By placing the sliding vane. (16, 50, 87)within the compressor housing, a plurality of working chambers (72, 49,53 and 106, 107, 108) are sequentially created within the crescentshaped cavity, delimited by the compressor housing inner peripheral (88)and the rotor outer surface (83). When compared with gas turbine enginecompressor, the rotary compression work is at least 2-15% more efficientas the fluid is sealed within the closed control volume (49, 107). Thecompression work within the crescent shape is smooth and gradual andtherefore the compression is nearly isentropic. As a result of therotation of the rotor, a periodic sequence of compressed fluid isdelivered to the exhaust port (56, 76) of the compressor housing. Therotary combustion engine compressor casing is sealed at its oppositeends by bolted (9) plates (10). One of the compressor end plates isapertured at its centerline to allow for the drive shaft.

FIGS. 1, 2 and 3 depict preferred embodiments where compressor andturbine housings are arranged in tandem. For such configurations, powerand torque transfer and synchronization of compressor and turbine rotors(12, 3) and valve rotation (67, 69) are achieved with drive shafts (31,8, 6, 69), gears (33, 28, 26, 24) or other transmission mechanisms (7,25, 30), and bearings (not shown) supported by the engine casing (32,21, 22, 23, 27). For the preferred embodiment depicted in FIG. 4, powertransfer between the turbine and the compressor is much simpler, as thecompressor (129) and turbine (117) rotors are directly coupled to thedrive shaft (110). The shaft is journalled in bearings supported by theengine casing (121, 122). The back-to-back compressor and turbineconfiguration is compact and lightweight as no gear, pulley andauxiliary power and torque transfer equipment is used. A fluid transferpassage (114) connects the exhaust port (76) of the compressor and theintake port (73) of the turbine. In the external combustion enginedepicted in FIG. 3, the said transfer passage includes a combustionchamber (74, 92) which is periodically pressurised by gas flow from thecompressor exhaust port. Downstream of said compressor exhaust portthere is at least one check valve and/or at least one cyclo-valve (67,68, 93), operating between open and closed positions, in timed sequencewith the passage of the turbine sliding vane (100). The closed position(94) of the said valve prevents gas flow from the combustion chamberinto the compressor. The cyclo-valve comprises a tubing (70) havinginlet and exhaust ports (71) and a rotatably and sealingly mountedslotted cylinder (69) within the said tubing.

Two firing cycles occur per rotor revolution. As one firing takes placein the chamber (91), new cycles in the chambers (92, 107, 108) arepreceding the present firing and at least one old cycle (60,99) isterminating thereof, a smooth operation is assured. The rotary turbineunit is similar to the compressor unit but its size differs. Workingchambers (60, 66, 103, 99), belonging to the turbine are delimited bythe housing inner peripheral (97), the rotor outer surface (98) and theside surface of the sliding vane (37). For FIG. 3, the combustionworking chamber (74) and the expansion chamber (103) are separate butlinked. Thus, the turbine housing is allowed to run at a reducedtemperature. A periodic sequence of expanded fluid is delivered from theexhaust port (34) with each rotation of the turbine rotor in response tohigh pressure and temperature gas expansion in the said turbine. Theexhaust gas pressure is lowered to about local ambient pressure valuesto allow maximum shaft work extraction and increase in thermalefficiency. As shown in FIG. 7, the maximum volume of the turbineexpansion chamber (66) is sized such that the combusted gas pressure(151 e, 151 f, 151 g) is expanded to local ambient pressure (151 h). Theheight of the turbine inner housing (36) and the turbine rotor (117) issized in such a way that, the pressure of the gas, as it is beingtransferred from the compressor chamber (72) is maintained to about aconstant high value (151 b). The turbine casing (35) is sealed at itsopposite ends by bolted (42) plates (43). One of the said plates isapertured at its centerline, to accommodate the drive shaft (31)protruding therefrom.

A fuel or a fuel/atomiser mixture (75) is supplied to said combustionchamber (74, 66) using commercially available fuel injection or fuelaspiration means. The fuel/oxidizer mixture is ignited usingcommercially available spark (91) or pressure ignition means. For each360 degrees of rotation of said compressor rotor, there are two completeis and consecutive cycles of intake (108, 151 a), compression (92, 151ab), combustion (74, 151 bce; 151 bcdf; 151 bcg), power (66, 103, 151eh; 151 fh; 151 gh) and exhaust (60, 99, 151 h) phases.

The thermodynamic cycle associated with the intake, compression,combustion, expansion and exhaust phases of the rotary engine containsinnovations when compared to the Otto, Brayton, Diesel or more recentincreased expansion cycles proposed in prior arts (PCT WO 02/090738,DUNCAN, Ronnie J. , Nov. 14, 2002: U.S. Pat. No. 5,341,771, RILEY,Michael B., Aug. 30, 1994). At intake, compression and combustionphases, the present invention combines the advantages of Otto and Dieselthermodynamic cycles. It is well known that for a given compressionratio, the ideal Otto cycle currently provides the most efficientcombustion/expansion process since it combines high peak temperatureduring the isochoric (constant volume) heat addition, while stillkeeping an acceptable mean chamber temperature. However, high peakcombustion temperatures can cause auto-ignition of a portion of fuel-airmixture, resulting in engine knocks. Diesel is an improvement of theOtto cycle as it provides higher useful compression ratios and isobaric(constant pressure) heat addition and do not have knock problem as airalone is present during the compression process. The high compressionratio makes Diesel engines more fuel-efficient but for this same reason,they also become much heavier. Compared to the Otto cycle, Diesel cyclealso delivers less power for the same displacement. For the compressionand combustion phases of the cycle, the ideal would be to follow alimited combustion pressure cycle that would first use a combinedisochoric heat addition followed by isobaric and/or isothermal heatadditions. As mentioned in a prior art, (U.S. Pat. No. 5,566,650, KRUSE,Douglas C., Oct. 22, 1996) such hybrid engine process has been developed(Texaco TCCS, Ford PROCO, Ricardo, MAN-FM and KHD-AD) but they have beenproven impractical. The rotary engine of the present invention naturallyfollows the above-described limited peak cycle (151 bce; 151 bcdf; 151bcg) multi-step (isochoric, isobaric and/or isothermal) combustionphases.

By limiting the peak combustion pressures, the present invention alsoprovides an expanded power stroke that improves power extraction (151eh; 151 fh; 151 gh). A search of the prior art did not disclose anypatents that considers a thermodynamic heat engine cycle, whether it bereciprocating or rotary, that jointly proposes a limited peak combustionpressure and an expansion phase where the pressure exhausts to aboutambient pressure.

One of the drawbacks of the current gas turbine engines are their highlysensitive stall characteristics always placed close to the highperformance region. Furthermore, shaft and aero-thermodynamic couplingand feedback loop between the compressor, and the turbine, only allows anarrow, high efficiency operational band. The present invention providesa practical and effective means of adding higher degrees of freedom tothe gas turbine engines by eliminating the shaft coupling between fans,compressors and turbines. The compound engine (FIGS. 8, 9, 10) of thepresent invention combines the efficiency of the heat engines with thecompactness, lightweight and high power characteristics of gas turbineengines. Heat engines can produce kilowatts of power at high powerdensities and efficiencies but they are heavy and of relatively largesizes. After 50 MW, most of thermodynamic scaling and costconsiderations have favoured large size gas turbine engines. 100 MW gasturbine combined cycle power plant costs about 500 USD per kW, whereas10 MW power plant costs 750 USD per kW and 1 MW power plant costs 1000USD per kW. For small power range (0.1-10 MW), internal combustionengine becomes highly competitive despite their size, weight and highmaintenance cost. The present invention overcomes the limitations ofboth small gas turbine engines and large internal combustion engines andmeets the modularity, high efficiency, mobility weight and costrequirements of today's modern power and propulsion applications.

The invention provides a preferred embodiment of a high mass flowpropulsion device. This is achieved by a mechanical coupling (162, 165,167) of the rotary engine components with conventional gas turbineengine components. The turbo-rotary compound engines (FIGS. 8, 9, 10) ofthe invention, eliminates conventional long and heavy concentric shaftsand disclose a novel configuration where conventional rotational wing(186), fans (153, 155) compressors (158, 161, 182, 197) and turbines(170, 171, 178, 191) are only aero-thermodynamically coupled with eachother. In this invention, rotary turbines (154, 156, 157, 163, 181, 188,196) drive said rotational wing, fans and compressors. Conversely, saidconventional turbines drive single or a plurality of rotary compressors(164, 166, 168, 179, 195, 190). Rotary compressors supply compressedfluid via flexible high-pressure connections (172, 187, 189, 194).Relatively low mass flow will move through such connection as bothrotary compressors and turbines are partial admission machines. Low massflow also favours the efficient use of intercooler (193) and reheat(198) systems, giving a further boost to thermal efficiency. Thecompound engine of the invention combines the thermal efficiency of therotary internal engine cycle and the high mass flow, compact size andlightweight of the gas turbine engines. Such a compound cycle propulsionengine may comprise propellers, conventional fans, contra-rotating fans,hub-turbine driven fans (177, 176), contra-rotating hub-turbine drivenfans (175, 174), axial and/or centrifugal compressor stages, combustionchambers (173), axial and/or centrifugal turbine stages, rotarycompressors and turbines, intercoolers and reheaters. The current designis versatile and simple, therefore well adapted to turboprop, turbofan,marine and land based power production and refrigeration applications.The subject design can also be applied to geothermal power plants.

As is demonstrated by the breath of this description, the range ofapplication for the compound and solo use of the turbo-rotary engineprovided by the invention is truly vast. In particular, the scope of thepresent invention includes hybrid turbo-rotary engines whereconventional axial and/or radial turbines drive both conventional axialand/or centrifugal compressors and rotary compressors. Also included inthe present invention, hybrid applications where conventional axialand/or centrifugal compressors are driven by both conventional axialand/or radial turbines and rotary turbines. While the description cannotaddress each and every application, it is intended to indicate theextensive capabilities contemplated by the invention.

1. A method of operating a heat engine having a sliding vane rotary vanecompressor and a sliding vane rotary vane turbine, comprising: thesequential steps of: a first step of intaking a fluid in an intake phaseinto a working chamber of the rotary vane compressor at ambientpressure; a second step of compressing the fluid in a compression phasein the working chamber by rotating a rotor of the rotary vane compressorup to 360° of rotation; a third step of mixing the compressed fluid witha fuel and igniting the mixture in an initial combustion phase in acombustion chamber external to both the rotary vane compressor and therotary vane turbine to carry out a limited temperature constant volumecombustion process; a fourth step of subjecting the combustion productsfrom the third step to a constant pressure combustion process in a finalcombustion phase followed by a power expansion phase in an expansionchamber of the rotary vane turbine by rotating a rotor of the rotaryvane turbine up to 360° so that the pressure of the combustion productswithin the turbine expansion chamber reaches ambient pressure or nearambient pressure when the turbine expansion chamber volume reaches itsmaximum; and a fifth step of exhausting the combustion products in anexhaust phase from the expansion chamber.
 2. A method according to claim1; wherein for each 360° of rotation of the rotors of the rotary vanecompressor and the rotary vane turbine, there are two complete andconsecutive cycles of intake, compression, combustion, power expansionand exhaust phases.
 3. A compound propulsion engine comprising: aprimary stage including an axial compressor having compressor blades anda rotary shaft defining an axial direction such that ram air iscompressed and exits the axial compressor in the axial direction, asliding vane rotary vane turbine driven by the exiting compressed airand connected by an interconnecting shaft to rotationally drive theaxial compressor, and a combustor that is disposed downstream of theaxial compressor and that adds heat energy to the exiting compressed airto produce combustion products; and a secondary stage including an axialturbine having turbine blades and a rotary shaft extending in the axialdirection and driven by the combustion products exiting the combustor,and a sliding vane rotary vane compressor connected by aninterconnecting shaft to the axial turbine so as to be rotationallydriven by the axial turbine, the sliding vane rotary vane compressorbeing connected to receive and further compress a portion of the ram airor a portion of the compressed air exiting the axial compressor toproduce a secondary compressed air flow that is directed through one ormore transfer passages to an intake of the sliding vane rotary vaneturbine.
 4. A compound propulsion engine according to claim 3; furtherincluding a reheater disposed in one of the transfer passages.
 5. Acompound propulsion engine according to claim 3; further including anintercooler disposed in one of the transfer passages.
 6. A compoundpropulsion engine according to claim 3; wherein the first and secondstages are aero-thermodynamically coupled to each other and are notmechanically connected together by a shaft.